<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="utf-8">
    <title>Flexbox</title>
    <style>
        section {
            display:flex;
        }

        article {
            padding: 10px;
            margin: 10px;
            background: aqua;
            flex: 1 150px;
        }

        article:nth-of-type(3) {
            flex: 2 200px;
        }
    </style>
</head>
<body>
<section>
    <article>
        <h2>First article</h2>
    </article>
    <article>
        <h2>Second article</h2>
    </article>
    <article>
        <h2>Third article</h2>
    </article>
</section>
</body>
</html>